I'm going out on the everglades with my girl for three days and two nights in mid Feb. We've done dispersed camping in the Midwest for several days, and the struggle has always been having enough water. We're going to be on a canoe for the entire time, (aside from camping for the 2 nights) and I'm wondering about two things:

1 - water - can anyone recommend collapsible container brands? The cheap amazon ones sometimes leak, so fuck 'em. Any better recommendations? Is 3.5 liters a day really enough for one person? I want to have 30/40 liters total for the two of us for 3 days, 2 nights. Is there a better method for water aside from collapsible containers?

2 - emergency protocol. - she wants to buy a flare, which I think only matters if people are already searching for you. You also can't take it on a plane, which makes it an unused expensive hassle that needs to be shipped back home. Based on my limited research, not a lot of people go missing in the everglades, so a flare wont help unless people are already looking for you. I don't want to spend the money on a VHF radio. Any recommendations for emergency situations? I feel like rolling dice based on my luck for the past two decades.